Tevis Howard, 29

Founder, KOMAZA

Tevis Howard's KOMAZA serves dryland subsistence farmers, the poorest population on Earth, with the lowest incomes, highest birth rates, and highest child mortality. The intervention: planting trees. By growing indigenous melia and hybrid eucalyptus, these farmers can reap income selling valuable timber for furniture and construction. KOMAZA provides most of the financing but requires farmers to contribute $2. Also helps replenish soil and prevents erosion.